The Gamma Herpesvirus Alcelaphine Herpesvirus 1 Causes Apoptotic Infection in Permissive Cell Lines

ABSTRACT

Apoptosis is a host defense mechanism that the cell uses to limit production of infectious virus. Although many viruses can induce apoptosis in infected cells, large DNA viruses, such as poxviruses, herpesviruses and adenoviruses, usually exhibit the ability to suppress the induction of apoptosis in the infected cells. Several publications have attested to the ability of herpesviruses to protect cells against apoptosis. We investigated the ability of the virus to protect cells in continuous cultivation from apoptosis induced by the virus itself. The gamma herpesvirus alcelaphine herpesvirus 1 (AlHV-1) has been shown to harbor genes with antiapoptotic potentialities. However, here we have demonstrated that productive infection of adherent, permissive cell lines by AlHV-1 resulted in a cytopathic effect characterized by induction of apoptosis. This phenomenon was confirmed using different techniques to detect apoptosis and using different virus strains and cell lines. Therefore, despite the presence of antiapoptotic genes in its genome, AlHV-1 could complete its cycle of productive infection while inducing apoptosis of infected cells. This finding might have implications for the pathobiology of AlHV-1 and other gamma herpesviruses in vivo.